Impact of Lockdown Measures during COVID-19 Pandemic on Pregnancy and Preterm Birth

Objective The objective of this study is to assess the effect of the lockdown measures during the coronavirus disease 2019 (COVID-19) pandemic on pregnancy outcomes of women who were not affected by severe acute respiratory syndrome coronavirus 2 infection. Study Design We used data from the perinatal health program and neonatal databases to conduct a cohort analysis of pregnancy outcomes during the COVID-19 lockdown in the Calgary region, Canada. Rates of preterm birth were compared between the lockdown period (March 16 to June 15, 2020) and the corresponding pre-COVID period of 2015 to 2019. We also compared maternal and neonatal characteristics of preterm infants admitted to neonatal intensive care units (NICUs) in Calgary between the two periods. Findings A total of 4,357 and 24,160 live births occurred in the lockdown and corresponding pre-COVID period, respectively. There were 366 (84.0 per 1,000 live births) and 2,240 (92.7 per 1,000 live births) preterm births in the lockdown and corresponding pre-COVID period, respectively ( p = 0.07). Rates of very preterm and very-low-birth-weight births were lower in the lockdown period compared with the corresponding pre-COVID period (11.0 vs. 15.6 and 9.0 vs. 14.4 per 1,000 live births, p = 0.02 and p = 0.005, respectively). There was no difference in spontaneous stillbirth between the two periods (3.7 vs. 4.1 per 1,000 live birth, p = 0.71). During the lockdown period, the likelihood of multiple births was lower (risk ratio [RR] 0.73, 95% confidence interval [CI]: 0.60-0.88), while gestational hypertension and clinical chorioamnionitis increased (RR 1.24, 95%CI: 1.10-1.40; RR 1.33, 95%CI 1.10-1.61, respectively). Conclusion Observed rates of very preterm and very-low-birth-weight births decreased during the COVID-19 lockdown. Pregnant women who delivered during the lockdown period were diagnosed with gestational hypertension and chorioamnionitis more frequently than mothers in the corresponding pre-COVID period.